| Journal: | Journal of the Brazilian Chemical Society |
| Database: | PERIÓDICA |
| System number: | 000311253 |
| ISSN: | 0103-5053 |
| Authors: | Cruz, Frederico G1 Cerqueira, Martins D. de Roque, Nídia F |
| Institutions: | 1Universidade Federal da Bahia, Instituto de Quimica, Salvador, Bahia. Brasil |
| Year: | 2003 |
| Season: | May |
| Volumen: | 14 |
| Number: | 3 |
| Pages: | 456-460 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, aplicado |
| English abstract | Methyl esters of diterpenoids ent-pimara-9(11),15-dien-19-oic acid (1), ent-pimara-7,15-dien-19-oic acid (2), and ent-pimara-8,15-dien-19-oic acid (3) were submitted to photooxygenation reactions with sensitized singlet oxygen. While compounds 2 and 3 were converted to the products, compound 1 reacted only partially, suggesting an influence of the steric hindrance on the endocyclic double bond of 1. The oxidation products obtained, methyl-7alpha,11beta-dihydroxypimara-8,15-dien-19-oate (5), methyl-7alpha-hydroperoxypimara-8(14),15-dien-19 oate (6), methyl-7alpha-hydroxy-14-oxopimara-15-en-19-oate (8), methyl-7alpha,9alpha-dihydroxypimara-8(14),15-dien-19-oate (9) and methyl-7alpha,14alpha-dihydroxypimara-8,15-dien-19-oate (10), are new and their structures were elucidated by spectral data analysis |
| Portuguese abstract | Ésteres metílicos dos diterpenos ácido ent-pimara-9(11),15-dien-19-óico (1), ácido ent-pimara-7,15-dien-19-óico (2) e ácido ent-pimara-8,15-dien-19-óico (3) foram submetidos a reações de fotooxigenação via formação sensibilizada de oxigênio singlete. Enquanto os compostos 2 e 3 foram totalmente convertidos nos produtos, o composto 1 reagiu apenas parcialmente sugerindo uma influência do impedimento estéreo sobre a ligação dupla endocíclica deste diterpeno. Os produtos de oxidação obtidos, 7alfa,11beta-diidroxipimara-8,15-dien-19-oato de metila (5), 7alfa-hidroperoxipimara-8(14),15-dien-19-oato de metila (6), 7alfa-hidroxi-14-oxopimara-15-en-19-oato de metila (8), 7alfa,9alfa-diidroxipimara-8(14),15-dien-19-oato de metila (9) e 7alfa,14alfa-diidroxipimara-8,15-dien-19-oato de metila (10) são inéditos e suas estruturas foram determinadas pela análise de seus dados espectrais |
| Disciplines: | Química |
| Keyword: | Química orgánica, Diterpenos, Ent-pimaradieno, Oxígeno singulete, Fotooxigenación |
| Keyword: | Chemistry, Organic chemistry, Diterpenes, Ent-pimaradiene, Singlet oxygen, Photooxygenation |
| Full text: | Texto completo (Ver HTML) |
